The present invention relates generally to methods and apparatuses for finishing the surface of a workpiece and, more particularly, the entire outer peripheral surface of a generally cylindrical workpiece. A specific disclosed embodiment in one preferred form relates to the finishing of piston ring faces.
The manufacture of piston rings, for example, of the type found in the ordinary internal combustion engine, is a sophisticated, many step process and briefly would typically include forming, for example, by casting, a hollow shell of ring material and slotting one edge of that shell after which the slotted shell is sliced to form the several C-shaped rings and each ring has its top and bottom (flat) surfaces finished and its face (that portion which typically engages the internal combustion engine cylinder wall) provided with a groove or ducted, depending upon the type of ring to be formed, whereafter that ring face is finished by a lapping process.
The typical ring face lapping process is carried out within a cast iron sleeve in the presence of a diamond abrasive compound requiring typically around 10 minutes to complete and, of course, inducing rather rapid wear in the cast iron sleeve requiring frequent replacement of those sleeves once they have experienced 6 to 8 one thousandths of an inch wear. Cleaning of the rings is also quite difficult after such face finishing and the abrasive medium is relatively expensive.